SCIENCE- GOSSIP. 



efficient "Fram." The mosl popular of Messrs. 

 Watson's microscopes appears to be the •'Edin- 

 burgh" stand, made in many forms of various 

 completeness, and we question if there is a more 

 popular stand upon the market. The newer stands 

 arc the ■• Royal " an " Edinburgh " microscope in 

 its completest form, with large tube — the "Circuit 

 Stage Van Heurck" (see S.CIENCE-GOSSIP, vol. vi. 

 p. 57), and the "Fram" and "School" micro- 

 scopes. The latter is a perfectly-made stand, 

 with excellent coarse, but no fine adjustment, 

 sold at the extraordinary price of £2 7s. 6d. We 

 are clad to see that one or two older and out-of- 

 date stands no longer find a place in the catalogue. 

 Of most interest, perhaps, are the new Holoscopic 

 series of objectives, eyepieces, and condensers. 

 We spoke in the highest terms of these objectives 

 when they first appeared (see Science-Gossip, 

 vol. vi. pp. 183 and 313), especially of the half- 

 inch of N.A. -65, which we considered an important 

 advance upon achromatic objectives hitherto ob- 

 tainable, and we note that the list now includes an 

 inch of N.A. -30, a quarter-inch of N.A. "95, an 

 eighth-inch oil-immersion of N.A. 1-35, and a 

 twelfth-inch oil-immersion of N.A. 1-4. Our 

 readers will observe that these apertures equal 

 those of the costly apochromatics. We hope to 

 speak again of these objectives shortly. The holo- 

 scopic eyepieces, which can be used with both 

 achromatic and apochromatic objectives, w r ere also 

 duly noticed in this journal (Science-Gossip, 

 vol. vi, p. 183), as was also the holoscopic immer- 

 sion condenser of N. A. 1-35 (Science-Gossip, 

 vol. vi. p. 57). No less than seven different forms 

 of photo-rnicrographic cameras are listed, including 

 a new 7 combined vertical and horizontal camera. 

 The whole catalogue is profusely illustrated, and 

 contains no less than 130 pages. 



Presekvation of Medusae.— The " Journal of 

 Applied Microscopy " says that medusae may be 

 killed by adding a few drops of concentrated 

 chromic acid to sea-water containing them. Then 

 well wash in sea-water until the chromic acid has 

 disappeared. Gradually add glycerine and alcohol 

 to water, until objects are in pure glycerine and 

 alcohol of same specific gravity as sea-water. 



ANSWERS TO CORRESPONDENTS. 



G. G. B. (Oldham). — For wood sections we prefer 

 Delafield's Haematoxylin. Squire's formula is as 

 follows : — To 400 cc. of a saturated aqueous solu- 

 tion of ammonia alum add 4 grams of haematoxylin 

 dissolved in 25 cc. of absolute alcohol ; leave the 

 solution exposed to the light and air in a stoppered 

 bottle for three or four days ; filter, and add to the 

 filtrate 100 cc. of glycerine and 100 cc. of methylic 

 alcohol (wood spirit) ; allow the solution to stand 

 in the light until it is a dark colour, re-filter and 

 preserve in a stoppered bottle. If you require a 

 red stain, however, we would suggest a 1 per cent, 

 solution of eosin in alcohol. Immerse in this for 

 ten minutes, wash in methylated spirit, clear in 

 clove oil, and mount in Canada balsam. Borax 

 carmine is generally used as a double stain with 

 acid aniline green. We gave a note on preparing 

 and mounting wood sections in Sciexce-Gossip, 

 vol. vi. p. 214. See a note also by Dr. P. Q. Keegan 

 on p. 60 of the present volume ; also our remarks 

 on staining in the present number in " Microscopy 

 for Beginners." F. S. S. 



EXTRACTS FROM POSTAL MICROSCOPICAL 

 SOCIETY'S NOTE-BOOKS. 



( Continued fi om page 185.' ) 



Notes by Wm. h. Bttrbidge. 



Polyp «/ Aleyoniuon palmatum (fig. 6). One of 

 the Arftflhozoa, i- of a higher organisation than 

 Hydroida. It is the cream-coloured, fleshy sub- 

 stance commonly called dead men's fingers. The 



protruded polj'p is an elevated tubular column of 

 translucent substance terminating in ai 

 flower of eight slender-pointed petals— the ten- 

 tacles of the polyp. " The spicules in this crea- 

 ture are of interest, being of varying forms ('-). 



f cries 



Pig. 6. Polyp of Alcyonium, 



In Alcyonium the sexes are separate, and even the 

 sexes of different colonies are distinct. In any 

 one commonwealth the individuals are either all 

 males or else all females. The ova and sj erm 

 masses are borne on stalked capsules upon the free 

 edges of the mesenteries, or straight bands that 

 run down the tube below the curled-up filaments, 

 and development takes place outside the parent. 

 The embryos are free, swimming by cilia. They 

 soon fix themselves, and by continued budding 

 produce colonies "' (Hornell). Stalked larva of 

 Antedon (fig. 7), better known by the name of 

 Comatula rosacea, or " feather-star." Mr. Hornell. 

 in his "Journal of Marine Zoology," describes the 

 delight with which he first pulled up. on a lobster- 

 pot, a colony of this most lovely of star-fishes. I 

 can also recall a red-letter day long ago when I 

 pulled up in a dredge a mass of these beauties in 

 Torbay, one of the greatest prizes. I think, round 

 our English coast. •• Its body consists of a disc 

 some half inch across, from which proceed ten 

 long slender arms bearing numerous pinnules on 

 cither side. These often reach 3| inches, so that 



(1) These extracts were commenced in the September number, 

 1900, at p. 119. 



(2 1 The spicules of Alcyonium and Gorgonia make beautiful 

 objects for polarizer and analjzer. — Ee. Microscopy. 



